Rivet



July 1941. c. E. HATHORN RIVET Filed Nov. 25, 195o FICA.

lNvENToR CAQLES E, HATHOQN.

Pnionied Joly s, 1941 UNITED- STATE s PATNT -oFi RIVET' Charles E. Hathorn, Kenmore, N. Y., assignor to Curtiss-Wright Corporation, a corporation oi' Delaware Application November z5, 1939, sonni No. 306,109

4olaiins. l (ci. :i5-'40) -This invention relates .to rivets', being particularly concerned with that Atype of rivet which is the bore Il, and an'enlarged head' 2| whose out-I adapted lto bel applied and driven from-one side onlyv of the sheets or plate to -be joined.

An object of the invention is to provide a hollow rivet adapted to be inserted through alined holes formedin. superposed sheets or plates of metal, .the rivet being drivable from the same lside of the work from which it is inserted.

A further objectoof .the invention consists in the provision of a rivet having a. bulge in its bore which bulge is adapted to'be expanded upon the the application of a suitable tool to form a head or protuberance. on the -inaccessible side of the plates.

Still another object is to provide a blind rivet,

' adapted to be applied and driven from the same serted mandrel through the rivet to form the headed portion' thereof.

side diameter is substantially the same as that of the Acounterbores I5 and I6. The sides of the vhead 2I are tapered as shown at 30. To driv'e the rivet, the mandrel I9 is iirst passed through the rivet from the shank end, and the' rivet and the mandrel are inserted together through the plates so that the shank protrudes outside of the rivet head I3. Thereupon, a plier-like tool is utilized, one jaw -of 'the plier grasping the shank 20 andthe other jaw bearing upon. the

head I3; By squeezing fthe pliers, the mandrel I9 is drawn through the hollow of the rivet, the

head 2| engaging the thickened wall I8 and forc- 15` ing same to expand to the position of Fig. 3 whereupon a bulge is lformed exteriorly of the rivet which rmly engages the inside surface of the plate II and'forms an inner head by which i the plates are securely attached lto one another.

. It is apparent that it would be possible'to eliminate the counterbore I6 without interfering' t with expansion of the 4thick wall I8, but the rivet important feature of the invention since the thin Further objects will .become apparent vreading the annexed detailed description in connec-V tion with the d'rawing; inwhich:

Fig. 1 is a perspective view of the rivet of this invention, before driving, shown partly in section;

prior to driving, showing the draw tool by which the rivet is driven; f

Fig. 3 is a section similar to Fig. 2 showing the driven rivet and the driving tool; and

Fig. 4 is a section similar to Figs. 2 and 3 showing an alternative form of driving tool.

In the drawing, superposed drilled to receive a rivet I2 which comprises a head I3 lying on the outside of the plates, and a cylindrical shank I4 passing through Ithe drilling. 'I'he rivet is hollow, as shown, comprising a. large counterbore I5 at the head end ofthe rivet and a similar large counterbore I6 at the shank end of the rivet, the bottoms of these counterbores being separated and joined by a through bore of smaller diameter, shown at I1. .'I'he,thick wall portion I8 formed by the bore Il is solocated that 50 of the plates I0 and it overlaps the thicknes II but lies predominanty clear' of the plates. Driving ofthe rivet is accomplished by means of a tool or mandrel, I9, comprising a shank 2li-of. such diameter that it may pass freely through Fig. 2 is a section through plates anda rivet i Yextension embodying the counterbore I6'is an walldeflned by theicounterbore I6 serves to prevent cracking vof .the thick wall I8 as the mandrel is drawn through the rivet. Initial attemptsin the design of a bulge rivet were largely unsuccessful since radial cracks developed in the thick wall I8 after same'had been expanded to form |the bulge, but the addition of Ith'e extension formed by the counterbore I6 solved the problemof eliminating the cracks.

It nhoum be further noted that the transition from .the small bore Il to the large counterbores I5 and I6 is accomplished through tapered shoulders 3| and 32 whoseftaper will be of a sulta angle determinable in accordance with the characteristlcs of the rivet material and the dimen-` plates II) and IVI are 40 sions of the rivet. -These tapered shoulders, in j conjunction with the Itaper 30 of the mandrel head, assure bulging of the rivet, without .bend- Vingthe internal collar formed within the rivet, but rather by smoothly owing 'the rivet material from an internal `bulge .to an externall bulge as at 33 witnmoderate local stresses in thefrivet material.

'Rivets of the type disclosed may beapplied where the metal sheets to be joined are loosely held, since the driving force `and reaction are wholly. assumed by the driving tool. However,' if'the plates are suiiiciently :firmly held.rivets of the type disclosed may be driven by applying the mandrel Il from the outside of the work and hammering same inwardly, whereby the thickened portion I8 is expanded from the outside toward the inside, rather than ,from 'the inside toward .the outside as would be the case when a plier tool is used. 4

In the showings of Figs. 2 and 3 it will be apparent that after driving, the rivet remains hollow. In some applications it is desirable to have a solid rivet for the-purpose of making a riveted container :duid tight. For this purpose a difierent form of mandrel may be used, such a mandrel being shown in Fig. 4.. This mandrel, indicated generally as 22, comprises a thin shank 23 necked in at its-bottom as at 2| whereat it is initially integral with a driving head 25 of cylindrical form, rounded at its upper end as at 25. 'I'he diameter of the mandrel portion 25 is substan-v tially equal to the diameter of the counterbores l5 and I5 of the rivet. The bottom of the mandrel portion 25 is provided with an undercut head 2l, the undercut being indicated-at 28. yIn utilizing this mandrel, the shank portion 2i!V is first inserted from the shank end of the, rivet l2 after which the rivet and mandrel Yare passed through 'the plates. Thereupon, theshank 23 is grasped by a tool, as previously described, and drawn outwardlywith respect to the rivet head I3. The tapered portion 26 of the mandrel engages the thickened portion I8 of the rivet, expanding same to join the metal plates. Further application of driving pressure sets the mandrel head 21 firmly against the bottom of the rivet causing a portion of the bottom of the rivet to deform and enter the undercut 28in the mandrel. Still further application of pressure causes parting of the shank v 23 from the mandrel portion 25 at the small section of the mandrel at 24, whereupon the mandrel portion 25 with its head 21 are left in the hollow of the rivet and are firmly secured from displacement by the engagement of rivet material in the undercut 28.

In any of the `above described mandrels, the materialof .the mandrel must be considerably harder and stronger than that of the rivet and the specific showings are based upon the use of either aluminum or copper `for the rivet, and steel for the driving mandrel. In the case of mandrels V-according to Figs. 2 and 3, the mandrel may be used over and over again for successive rivets. It will also be appreciatedthat although protruding rivet heads are shown, the rivet heads may be' countersunk in the material and the rivet heads may partake of any of the forms well known in the art.

While I have described my invention in detail in its presentv embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof, I aim in the appended claims to cover all `such modifications and changes.

I claim as my invention:

1. A blind rivet for securing metallic sheets in juxtaposition comprising a head having a shank of substantially uniform Vexternal diameter extending therefrom, said rivet having concentric 'bores of the same diameter extending from each end of the rivet toward the middle of the shank and defining a shank mid portion, said mid portion having a through hole of a diameter smaller than that of said bores defining thereby an annular collar integral with the shank and within the rivet, the ends of said collar comprising conical frusta whose conical elements are slanted with respect tothe cylindrical elements of the rivet shank bores.

2. A unitary blind rivet, comprising a head l having a bore of D diameter, arst shank portion adjacent the head having a'bore of D diameter, a second shank portion contiguous with the first having a tapered bore of D diameter at its end adjacent the first portion and d diameter at its other end, d being less than D, a third portion contiguous with the second having` a cylindrical bore of d diameter, a fourth portion having a tapered bore voi d diameter at its end adjacent the third portion and of D diameter at its other end, said shankportions together having a uniformouter cylindricalY shape.

3. A unitary blind rivet, comprising a head having a bore of D diameter, a first shank portion adjacent the head having a bore of D diameter, a second shank portion contiguous with the first having a tapered bore of D diameter at its end adjacent the first portion and@ diameter at its otherend, d being less than D, a third portion contiguous with the second having a cylindrical bore of d diameter, a fourth portion having a tapered bore oi d diameter at its end adjacent the third portion and of D diameter at its other end, and a fifth portion having a cylindrical bore of D diameter contiguous with the fourth portion,

said shank portions together having a uniform' outer cylindrical shape.

4. A unitary blindrivet, comprising a head hav.- ing ,a bore of D diameter, a first shank portion adjacent the head having. a bore of D diameter, a second shank portion contiguous with the first having a tapered bore of D diameter at its end adjacent the first portion and d diameter at its other end, d being lessthan D, a third portion contiguous with the second having a cylindrical bore of d diameter, a fourth portion having a tapered bore of d diameter at lits end adjacent the third portion and of D diameter at its other end, said shank portions together having a uni- V form outer cylindrical shape, said rivet being I adapted for driving by drawing a mandrel through the several rivet portion bores, the mandrel including a stem of less than d diameter and av tapered head whose greatest diameter is no greater than D. f

l CHARLES E. HATHORN. 

